1. Field of the Invention
The present invention relates in general to flying shears and punches. In particular, the present invention relates to an improved cutoff device for notching and shearing exterior siding panels.
2. Description of the Related Art
Exterior siding panels of aluminum, steel and plastic for application to buildings have been known for many years. It is often the case that the siding panels are produced as a continuous strip of material which is cut to the appropriate length and shape.
In particular, the longitudinal ends of most siding panels are not simply a straight shear line, but include notches along the lateral edges which open onto the longitudinal ends of the panel section. The upper notch is typically referred to as a hanger notch, while the lower notch is typically referred to as a butt notch. As noted above, each of these notches extends into each longitudinal end of each siding panel.
To form these notches and to cut the panels to the proper length, it has been common in the art to employ a single punching operation. In particular, a flying punch was employed which traveled with the uncut panel to match its speed. Once the speed was matched, the punch was actuated to remove a slug from the length of panel. The punch and die, and thus the slug, was in the general shape of an "I". In this manner, the upper and lower cross bars of the "I" would form the hanger and butt notches of adjacent ends of two panels. The elongated member connecting these cross bars would serve to separate the adjacent ends of the two panels.
While this arrangement provides the proper notches and panel cutoff, several problems are associated with this system. First, the slug produced by the previous system produces waste in materials. Specifically, the width of the elongated member connecting the crossbars in the "I" slug is all wasted material, as it is merely desired to separate the panels along this line. Additionally, the portion of the crossbars which correspond to the width of the elongated member is also waste. Second, the shape of the slug makes it very difficult to eject from the punch, which can result in the slug hanging up in the system. This may eventually cause a malfunction and interrupt production of the siding while the jam is cleared. Finally, the irregular shape of the slug also makes it difficult to recycle. The "I" slugs often become entangled in the recycling (grinding) machines, causing such machines to jam. This difficulty in recycling has often led to the slugs merely being discarded which is detrimental to the environment and a waste of resources.